In the related art, for example, as disclosed in Japanese Unexamined Patent Application Publication No. 2011-210102, a drive assistance device such as a collision avoidance assistance device that performs collision avoidance assistance with respect to an obstacle present in the vicinity of a vehicle is known. When detecting a situation where a collision cannot be easily avoided by normal steering or braking, such a device executes the collision avoidance assistance by performing an alarm notification, a steering intervention, a braking intervention, an operation of a safety device, or the like.